Results
Successful delivery of critical foundation and drainage works for the 87m high dam.
Construction of Australia’s tallest RCC dam, with a 78 GL storage capacity.
Two years of scaling and drilling completed safely within restricted access conditions.
Seamless execution of multidisciplinary works by a single contractor, reducing interface risks.
Project
Solution
Hydraulic winches installed to safely move drilling rigs into galleries.
Primary to quaternary grouting completed to form a 60m deep grout curtain.
Automated grout injection system with real-time monitoring.
Pressure relief drains drilled with extremely low deviation tolerances.
Integrated delivery of rock bolting, drainage, depressurisation drilling, and rock scaling.
Project
Challenges
Restricted access inside steep galleries at 42° inclines.
Confined working environment requiring precise grouting operations.
Stringent deviation tolerances for long pressure relief drilling up to 65m.
Requirement to manage multiple interdependent activities over several years.
Project
Overview
As part of the Enlarged Cotter Dam project in the ACT, complex foundation grouting and drainage works were delivered to support the construction of Australia’s tallest roller compacted concrete (RCC) dam.
Hydraulic winches were used to haul drilling rigs up 42° gallery inclines, gaining 80m elevation, where grouting was undertaken in confined spaces to enable construction to progress above. A fully automated grout injection system with Jean-Lutz instrumentation provided real-time monitoring to ensure strict criteria were met. Works included the 60m deep grout curtain beneath the 330m long dam wall, low-deviation pressure relief drilling, drainage installations, and extensive rock scaling.